Ketogenic Diet May Help Regulate Menstrual Cycles, New Study Finds

New research suggests that increasing ketones in the blood through a ketogenic diet or supplements may help regulate irregular menstrual cycles and potentially restart periods that seem to have stalled. In a recent study published in *PLOS ONE*, researchers compared the weight loss results from low-fat and ketogenic diets, with and without ketone supplements, and found promising outcomes among pre-menopausal participants.

Of the 13 participants who achieved nutritional ketosis, 11 reported changes in their menstrual frequency or intensity during the intervention, while those on low-fat diets reported no changes. All participants lost a similar relative percentage of weight during the study, which lasted six weeks. Madison Kackley, the lead author and a research scientist at Ohio State University, highlighted a remarkable outcome: "There were six women who hadn't had a period in over a year — who felt like their typical cycles were over. And their periods actually restarted on the diet." This suggests that the presence of ketones may influence women's health by regulating endocrine, cognitive, and metabolic factors.

The study involved 19 women, divided into three groups: seven on a ketogenic diet alone, six on a keto diet with ketone salt supplements, and six on a low-fat diet. Researchers provided all meals during the study, which led to clinically significant weight loss, reductions in body fat, improved cholesterol levels, and enhanced insulin sensitivity across both diet groups.

Interestingly, participants' self-reports regarding their menstrual cycles were unexpected. Kackley noted, "It's not a validated survey, but when we reviewed responses, we realized we were changing the majority of these women's cycles. Even for women who had normal menstrual cycles, their frequency changed." One participant, aged 33 and who had never had a period, experienced her first menstruation after just five days in nutritional ketosis. Notably, women who reported menstrual changes were not on birth control, whereas those who reported no changes were using oral contraceptives.

While ketone salts did not lead to improved weight or health markers, all women on the keto diet exhibited high ketone levels, indicating a potentially individualized effect of added ketones. Kackley explained, "It was just the presence of ketones that essentially changed the menstrual cycle. If we're looking for that signaling effect rather than just a weight loss effect, ketone supplementation could actually play a role in hormonal regulation."

Looking ahead, Kackley aims to further investigate the mechanisms behind this association, having established a new lab at Ohio State focused on the links between nutrition, exercise, and women's health. Her team is monitoring a pilot group of women to gather comprehensive data on the changes that occur during menstrual cycles, including muscle strength, fat composition, water retention, energy expenditure, hormone levels, and body temperature. Kackley believes this data will shed light on cyclical changes related to nutrition and exercise.

This research holds significant importance, especially since 5 to 7% of women of reproductive age in the U.S. experience three months without a period annually. Kackley emphasized the need for this research: "There are so many unanswered questions for women. We're trying to change things for women and give them some control — something we historically haven't had over our reproductive status."

The Department of Human Sciences at Ohio State's College of Education and Human Ecology funded Kackley's lab, while Metagenics Inc. provided the study supplements. The study included contributions from several co-authors at Ohio State and Metagenics.